In this paper, we have presented experimental results for preparation of Fe3O4-graphene nanocomposite that uses an ultrasound assisted method. The graphene oxide (GO) was prepared from graphite powder using modified Hummers-Offeman method. Subsequently, the synthesis of graphene-Fe3O4 nanocomposite was carried out by ultrasound assisted co-precipitation of iron (II) and (III) chlorides in the presence of GO. The formation of GO and graphene-Fe3O4 nanocomposite was confirmed by X-ray diffraction (XRD), Energy dispersive X-ray (EDX) analysis and Fourier transform-infrared (FTIR) analysis. The particle size of Fe3O4 nanoparticles loaded on graphene nanosheets (observed from TEM image) was found to be smaller than 20 nm. The use of ultrasonic irradiations during synthesis of graphene-Fe3O4 nanocomposite resulted in uniform loading of Fe3O4 nanoparticles on graphene nanosheets. The prepared graphene-Fe3O4 nanocomposite material was used for the preparation of anode for lithium ion batteries. The electrochemical performance of the material was tested by cyclic voltammetry (CV) and charge/discharge cycles. It was observed that the capacity of Li-battery when the anode material was made using graphene-Fe3O4 nanocomposite showed stable electrochemical performance for around 120 cycles and the battery could repeat stable charge-discharge reaction. (C) 2014 Elsevier B.V. All rights reserved.